Retinal detachment is a common cause of severe vision loss. In retinal detachment, the retina pulls away from the layer of blood cells which provide oxygen thus leaving the retinal cells lacking oxygen. Retinal detachment can occur when vitreous fluid leaks through a retinal hole or tear and collects underneath the retina. Tears or holes in the retina can occur for a number of reasons including disorders or aging that causes the retina to thin. A tear typically develops when there is a sudden collapse of the vitreous thus causing tugging on the retina with enough force to cause a tear. Fluid inside the vitreous may then travel through the tear and collect under the retina thus peeling it away from the underlying tissues which provide oxygen. In areas in which the retina is detached and the cells lack oxygen, vision may be lost if not treated quickly.
Rhegmatogenous retinal detachment is the most common etiology and is caused by a tear or hole that is usually in the peripheral retina.
Retinal detachment itself is painless, however symptoms are usually present before it occurs or advances. Symptoms of retinal detachment include the appearance of a large number of floaters; sudden flashes of light in the affected eye; and a shadow over a portion of the visual field that develops as the detachment progresses.
Several conditions may increase the chance of retinal detachment including nearsightedness; previous cataract surgery; eye trauma; previous retinal detachment in the other eye; family history of retinal detachment; or weak areas in the retina.
The principles of retinal detachment repair include identifying and treating the retinal breaks; draining the subretinal fluid; and internal or external tamponade of the breaks using scleral buckling or intravitreal gas or oil. Drainage of subretinal fluid is currently performed ab externo using an external sclerotomy, or ab interno using a drainage retinotomy. However, these techniques have significant disadvantages and complications. For example, external drainage with a sclerotomy requires an extensive dissection and cannot be done while directly visualizing the retina. External sclerotomy can also be complicated by hemorrhage, retinal incarceration, or iatrogenic retinal damage. Drainage retinotomy can be complicated by hemorrhage, recurrent detachment, or proliferative vitreoretinopathy. Internal drainage requires creating an iatrogenic retinal break.
Given the disadvantages in the current techniques for treating retinal detachment, what is needed is a device and system which would allow drainage site selection, drain placement and subretinal fluid drainage under direct visualization using an internal wide angle viewing system. Such a system would improve safety during drainage and avoid complications such as retinal incarceration and iatrogenic retinal breaks. A drainage retinotomy, which requires the creation of a posterior iatrogenic retinal break, can also be avoided.